From 2004 to 2012, 90% of dolphins stranded on Costa Rican beaches were scratched. According to Keto, in one year, between 10 and 15 dolphins come ashore. Only in 2012, reports the eight cetacean stranding. Of these, three were striped dolphins (Stenella coeruleoalba).
“We do not know the reason why that particular species is the most stranded, ” said Gabriela Hernandez, head of the microbiology section medicoveterinaria the National Animal Health Service (SENASA) and veterinary Keto.
A grounding or stranding occurs when a dolphin or whale generally approaches the coast and can not return to deep water on their own.
In Costa Rica, more cases reported in the Pacific than in the Caribbean. For Hernandez, it may be because there is underreporting of cases in the Atlantic slope.
Also, the vet said that they attended more juveniles and young adults.
“It would mean that they are healthy animals should be played. Dolphins are considered bioindicators, this means that if they are going out to the beach is because there is something in the ecosystem that is affecting, “Hernandez said.
Possible causes. In Costa Rica, some strandings are due to the interaction of these animals with humans, it may be that the dolphin can be caught in nets or trammel nets (entanglement) or be beaten by tourist boats and fishing.
For that reason, the country has a regulation governing whale watching boats to remain at a safe distance from the animal to avoid affecting their mobilization or hit them.
Also, cetaceans aground, because are sick due to the action of viruses, bacteria, parasites and toxins.
“They have attended two dolphins in areas affected by red tide and a baby that ate plastic,” Hernandez said.
Now, a study published in the journal Emerging Infectious Diseases (2008) analyzed 10 striped dolphins that stranded between 2004 and 2007 in the Pacific coast of Costa Rica, which had trouble swimming because neurological and died hours later.
“All the dolphins had antibodies to Brucella,” it said in reference to studying the bacteria that causes a chronic disease called brucellosis, which affects the central nervous system, and reproductive systems of these marine mammals.
The study also explained: “Stenella coeruleoalba constitutes a highly susceptible host and a potential reservoir for transmission of Brucella ceti in the Eastern Tropical Pacific.”